[Arny Krueger]

"Ian Bell" wrote in message

Arny Krueger wrote:
"Ian Bell" wrote in message

Eeyore wrote:
Ian Bell wrote:

Since there are untold preamp designs with unregulated
supplies
Bad preamps you mean ?

Graham


You tell me. I have the schematics for many broadcast
consoles and professional music mixers from the 50s that
use unregulated supplies.

Standards for audio were a lot lower in the 50s, if you
didn't ever notice when you listened to a lot of
recordings from that time. There are some exceptional
recordings that still sound good, but in general, it was
not a good time for quality sound reproduction.

I would not say they were a lot lower.

I lived back then, trust me, the standards were in general far lower. Good
sound of sorts did exist, but it was pretty rare.

Things perked up a lot in the 60s and 70s.

The flat bandwidth
extended only from 50Hz to 15KHz

....and that was a joke. Most audio reproduction systems of the day were in
trouble at 100 Hz, let alone 50. Today we can take response down to 20 Hz
seriously.

Note that speakers of that time in general were not capable of much acoustic
output by modern standards.

Other than a few very expensive microphones, the mics were about as bad as
the speakers.

but elsewhere the specs
were close to today's. An RCA broadcast console achieved
a 68dB S/N ratio with a -60dBm input signal which implies
an equivalent input noise of -128dBm - and that would not
be achievable with the LF noise I am seeing right now.

I suspect that you're looking at a transformer-coupled mic input, which says
nothing about the dynamic range of the console's output.

Furthermore, a transformer-coupled mic input can be made with wonderful
specs, since the transformer in essence covers up a lot of the sins of the
active components. But, the transformers of the day weren't all that
wonderful, either.

Maybe they had better conditioned mains supplies for
studios or maybe there was just less crap on the mains in
those days.

As a rule, audio people's standards were a ton lower in those days.

For example, I remember the regional 45 of The Righteous Brothers "You've
lost that loving feeling". It was hissy, boomy, dull sounding, and had some
pretty massive low frequency transients.

Listening to original oldies from the 50s, whether classical or pop can be a
lot of fun, but you don't do it for the high fidelity. Even the so-called
SOTA recordings, RCA Red Seal for example, had a great many clearly audible
flaws. I love the playing by the artists of the day, though. Toscanini is
one of my favorites, but listening to him conducting is about the music, not
the sound quality.